Why and How is the self related to the brain midline regions?

Abstract

What the self is and where it comes from has been one of the great problems of philosophy for thousands of years. As science and medicine have progressed this question has moved to also become a central one in psychology, psychiatry, and neuroscience. The advent of in vivo brain imaging has now allowed the scientific investigation of the self to progress further than ever.Many such imaging studies have indicated that brain structures along the cortical midline are particularly closely related to self-specific processing. This association between cortical midline structures (CMS) and self is reinforced by the involvement of these regions in other self-oriented processes, such as mind-wandering or stimulus valuation. Those midline regions involved in selfprocessing also overlap with another network, the default mode network, which shows high brain activity during the so-called resting state, indicating that there may be a special relationship between self-processing and intrinsic activity.Although such promising groundwork linking the self and CMS has been carried out, many questions remain. These include: what features of the midline regions lead to their apparent importance in self-processing? How can we appropriately account for confounding factors such as familiarity or task-effects in our experiments? How is the self-related to other features of the mind, such as consciousness? How is our methodology influencing our attempts to link the self and the brain?The purpose of this ebook is to address some of these questions, including opinions, perspectives, and hypotheses about the concept of the self, the relationship between CMS and the self, and the specific function of these brain regions in self-processing. It also includes original research papers describing EEG, fMRI, and behavioral experiments investigating different aspects of the self.The included papers can be roughly divided into four groups as follows: the first group of papers both collate existing evidence that midline structures are involved in self-processing and produce evidence for new facets of it. Reviewing the literature, Knyazev (2013) provides an overview of existing EEG studies of self-related activity, highlighting an overlap between self-related activity and rest, as well as the apparent importance of the P300 ERP and alpha activity in self-processing. Similarly, Araujo et al. (2013) present a meta-analysis of imaging studies that associates the medial prefrontal cortex (mPFC) with self-traits, in contrast to posterior regions which are more associated with the traits of others. In an fMRI study, Qin et al. (2013) show that self-related stimuli interact differently with intrinsic activity in the auditory cortex than do non-self-related. This finding provides backing for the hypotheses that self and intrinsic activity are particularly related. Looking at how self-trait priming affects task-performance, Bengtsson and Penny (2013) present experimental results and a Bayesian computation model for the effects observed. Finally, Colton et al. ...